YSI ProSolo Fluorescence-Based Portable Dissolved Oxygen Meter

Overview

The YSI ProSolo Fluorescence-Based Portable Dissolved Oxygen Meter is an engineered field instrument designed for high-fidelity, maintenance-lean dissolved oxygen (DO) measurement in aqueous environments. It employs phase-fluorometry — a non-consumptive optical detection principle — where molecular oxygen quenches the fluorescence lifetime of a ruthenium-based luminophore immobilized on the sensor surface. This method eliminates oxygen consumption at the sensing interface, removing flow-dependence, stirring artifacts, and membrane-related drift common in Clark-type electrochemical sensors. As a result, the ProSolo delivers stable baseline performance with minimal calibration frequency, making it suitable for long-duration deployments, regulatory-compliant monitoring, and applications demanding trace-level sensitivity and reproducibility across variable hydrodynamic conditions.

Key Features

• Optical DO sensing with no oxygen consumption, enabling accurate measurements independent of water velocity or mixing intensity
• Dual-range DO reporting: 0–500% air saturation (0–50 mg/L), supporting both low-oxygen hypolimnetic profiling and supersaturated effluent monitoring
• Smart digital sensor architecture: calibration coefficients, serial number, and sensor history are stored onboard the probe — enabling plug-and-play compatibility across ProODO-series hosts without reconfiguration
• IP67-rated ruggedized housing with dual-compartment sealing: battery chamber and electronics bay are physically isolated, preventing circuit damage even if the battery compartment floods
• Ergonomic overmolded rubber grip and chemically resistant polycarbonate body, validated for 1 m drop resistance and extended field service life
• Integrated barometric pressure sensor (50–110 kPa, ±0.2 kPa accuracy) for real-time atmospheric correction of saturation calculations
• Two operational modes: manual single-point sampling and continuous real-time logging (T₉₀ = 25 s, T₉₅ = 45 s)
• Backlit LCD with luminous keypad for low-light operation, including nighttime field surveys and indoor lab use under dim illumination
• Field-replaceable optical sensor cartridge — users can perform full sensor swaps in under 90 seconds without tools or recalibration
• USB 2.0 interface supports both data transfer and host power delivery via included cradle and cable

Sample Compatibility & Compliance

The ProSolo is compatible with freshwater, seawater (0–70 ppt salinity, manually entered for automatic compensation), wastewater, aquaculture systems, and laboratory BOD bottles (300 mL standard). Its optical design renders it immune to interference from hydrogen sulfide (H₂S), chlorine, carbon monoxide, and other redox-active gases that compromise amperometric DO sensors. The instrument complies with international environmental monitoring standards including ISO 5815-2:2019 (water quality — determination of biochemical oxygen demand after n days — Part 2: Method using diluted sample and seeded culture), ASTM D888-22 (standard test methods for dissolved oxygen in water), and EPA Method 360.1. Its construction meets RoHS, CE, WEEE, C-Tick, and VCCI electromagnetic compatibility directives. The IP67 ingress protection rating ensures reliable operation during submersion, rain exposure, or high-humidity laboratory environments.

Software & Data Management

Data Manager software (Windows-compatible) provides comprehensive configuration, visualization, and export capabilities. Users may define up to 100 custom site folders with metadata tagging (operator ID, location coordinates, project code). Each of the 2000 internal memory records includes timestamped DO, temperature, pressure, salinity input, sensor status flags, and user-defined annotations. Export options include CSV, Excel, and PDF report generation with embedded graphs and statistical summaries (min/max/mean/stdev). While the software itself does not enforce 21 CFR Part 11 audit trails, its structured metadata schema and immutable timestamping support GLP/GMP-aligned documentation workflows when deployed within validated laboratory information management systems (LIMS).

Applications

• Wastewater treatment plant process control: aeration basin optimization, return activated sludge (RAS) monitoring, and final effluent compliance verification
• Environmental field surveys: riverine DO profiling, lake stratification studies, wetland health assessments, and stormwater outfall screening
• Aquaculture and aquarium management: precision DO dosing in recirculating aquaculture systems (RAS), broodstock tanks, and coral propagation facilities
• Academic research and teaching labs: undergraduate water chemistry experiments, graduate-level biogeochemical cycling investigations, and sensor validation studies
• Industrial cooling water and boiler feedwater monitoring where chemical interference or low-flow conditions preclude electrochemical approaches
• Emergency response and rapid assessment: portable deployment for post-spill DO mapping or algal bloom impact evaluation

FAQ

Does the ProSolo require membrane replacement or electrolyte refilling?
No — the optical sensor uses a solid-state luminophore layer housed in a replaceable cartridge. No membranes, gels, or liquid electrolytes are involved.
Can the instrument be used in seawater without recalibration?
Yes — salinity is manually entered and automatically applied to saturation calculations. No recalibration is needed for salinity changes.
Is the USB interface capable of powering the device during data download?
Yes — the included USB cradle supplies bus-powered operation, eliminating the need for battery insertion during desktop data transfer.
What is the expected lifetime of the optical sensor cartridge?
YSI specifies a nominal 12-month functional lifespan under typical field use; performance degradation is gradual and detectable via routine zero-point checks.
Does the ProSolo support multi-parameter expansion (e.g., pH, conductivity)?
No — the ProSolo is a dedicated DO/temperature/pressure platform. For multi-parameter capability, YSI’s ProPlus or EXO platforms are recommended.